Compressed-air apparatus for operating pneumatic tools.



C. 0. PALMER.

COMPRESSED AIR APPARATUS FOR OPERATING PNEUMATIC TOOLS.

APPLICATION FILED APR. 18. i914.

Patented Sept. 28, 1915.

mM/Mii- K Witnesses:

COLUMBIA PLANDORAPH C0" WASHINGTON. D- E.

CHARLES orIs'rALivinn, or CLEVELAND, omo.

COMPRESSED-AIR APPARATUS EOR. OPERATING PNEUMATIC TOOLS.

Specification of Letters Patent.

Original application led August 21, 1909, Serial No. 514,029. Divided and this application led April 18,

To all whom it may concern:

Be it known that I, CHARLES Oris PALMER, a citizen of the United States -ofAmerica, residing at Cleveland, in the county of Cuyahoga and State of Qhio, have invented certain new and useful mprovements in Compressed-Air Apparatus for Operating Pneumatic Tools; and I hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

My invention relates to closed air apparatus for operating pneumatic tools such as power picks, rock-drills, power hammers, etc., in which the motor is operated by reciprocatory columns of compressed air from the pulsator through pressure connections which connect the ends of the motor and pulsator cylinders. And is a division of my application Ser. No. 514029 led Aug. 21, 1909 for compressed air apparatus for operating pneumatic tools, and is also a modification of the pulsator shown in my appli'- cations Serial No. 369,258 for a compressed air system iiled April 20, 1907 and for a compressed air apparatus, Serial No. 393,333, filed Sept. 17, 1907.

Chief among the objects herein sought is to produce a pulsator that will raiseA the pressure in the motor cylinder especially in the. beginning of its stroke andthereby make the motor more eifective. The pulsator is operated by an electric motor while the air motor is run from the pulsator.

In the accompanying drawings Figure 1 is a plan view partly in section of the pulsator embodying my invention with the motor connected; Fig. Q is the same section of the pulsator as Fig. 1 with the piston on the return stroke, Fig. 3 isa section of a valve on a smaller scale'that may be used to admit outside air to the auxiliary compressor at the point K1 of Fig. 1 if so desired. Fig. 4 is a section on line 1 -4 of Fig. 2.

The same characters denote the same parts throughout the several views. The larrows on the moving parts show the direction of their motion, and the arrows in the air passages the direction of the air, at the time shown and described.

Roughly stated` my invention comprises an airA or gas) pulsator cylindery with its piston therein dividing its air space into two compartments, means to reciprocate said piston, an equalizer air chamber, ports con- 1914. Serial No. 832,920.

necting it with both ends of said cylinder, an equalizer valve in both of said ports and means to positively yoperate said valve from a moving partv ofthe pulsator to open said ports'alternately and in time with the pulsator piston, an air motor pressure connection opening into the air compartment on the front side of the pulsator piston, an air motor pressure connection opening into the air compartment on the rear side of said piston, one of saidmotor pressure connections being preferably in an aforesaid connecting port and the other in the end of the pulsator cylinder opposite from that of said port connection. Also in the details of construction of the aforesaid equalizer valve. All of which will be hereafter described and pointed out in the claims.

The pulsator comprises a frame A at one end of which is secured a cylinder G. In the ends of the pulsator cylinder are formed the clearance spaces J1 and J2 which are here considered as part of the cylinder. For the purposes of this description the confined air in the pulsator cylinder and its connections is divided into two compartments by the pulsator piston P. An equalizer chamber H is connected to both ends of the cylinder by the ports S and S2 that are controlled by the positively driven valve V1. The motor cylinderv T is connected with the rear compartment through the tube F2 and with the front compartment through the tube F1 and channel P1. The spool shape equalizer valve I have found best adapted to the design necessary for fulfilling the various functions required of my pulsator as herein described.

rlhe piston P is connected to the pitman which is operated by the main crank from the crank shaft, which is in turn driven by the gear Gr that engages a-pinion on an electric motor (not shown). Or the gear may be driven in any other suitable manner.

The auxiliary compressor K may be oper-` ated from the crank K3 on the crank shaft as shown or by any other convenient means.

A bit or chisel (not shown) of the required form is held by the end of the motor piston T2 and operates on the coal or other material.

The proper working of the motor is dependent on an approximatel balance of pressure being maintained on the opposite sides of the motor piston. When this balance is not maintained the motor piston staysy Patented Sept. 28, 1915.

nearer to one end of the cylinder thanthe other and does not have a long free' 'stroke it should. Thisloss of balance may be, pro* duced by leakage of air from one of thev lcompartinents to the atmosphere as by a eakage in a tuber connection, or fromn one compartment to the other compartment, las by air slipping` by the motor piston, etc.

To preserve the pneumatic methods have been resorted to. In my irnproved pulsator shown in Fig. VlY the equal'- iZer valve V1 connects the high pressure end 'of cylinder C with the Vequalizer chamber H as follows. The valve V1 is operated by the crank or eccentric N on the crank shaft throiigh the valve rod as here shown or in anyother suitable manner. On the return stroke of the pulsator piston P, the valve V1 is moved toits forward position (see Fig. 2) the air chamber H is connected With Athe back end (now the high pressure end) of the pulsator cylinder. The equalizer chamber H is thus alternately connected, first through the port S with the'front air compartment;l

and then by the port S2 of the pulsat'or cylinder C With the rear compartment. As each compartment is connected with the air chamber H it assumes the same pressure as said chamber Hence if each compartment; has the same pressure as the air cham'-Y be'r H then each has the same pressure as the other compartment and the apparatus is bal- This f supposes the uniform, and for the it is suiiiciently true.

There is this difference in the operation of the parts on the opposite endsv of the pulsator cylinder. In the front (or lower purpose 'of balancing,

end on the drawing) of the cylinder C Whenl the valve Vl first opens, the air rushes from 'chamber H directly inte the passage Pl and the tube F1 to the motor cylinder7 Without i'rst entering and 'raising the pressure in the Whole pulsator cylinder. In other Words 'the cylinder C is being filled from chamber H at the same time that the motor cylinder lis being filled so that no time is lost. But in the back (or upper end on the drawing) the air mustpass from chamberll into cylind'er C before it passes into the motor cylinder through tube F2, and therefore rtime is lost in raising the pressure in the Whole pulsat'or cylinder before its full effect is felt in the motor cylinder. This loss of time in reaching vthe maximum pressure in the motor cylinder decreases thepoiver inthe y motor 'cylinder (other things being equal) land thus' lowers the effectiveness of' the motor.

lAs .already described the pneumatic balance made by yconnecting the equalizer chamber H with the compartment that was on 'the high pressure side. of the pressor pis-ton. By turning the gear G in the oppo- 'otherl Words novv balance several Y site direction fromthat shownvin Fig. land 'above described WhatY 'vas the high pressure Sid4 of the pulsator piston becomes the low pressureside, 'and "the air vchamber H that formerly Was connected only With` the VVhigh pressure compartment is novv connected only with the low` pressureV compartment. In the pulsator in the beginf ning of its stroke, takes airr from the chamber andthe lovv pressure side of the mctor piston, deliversit to the high Vpressure side ef the n'ietor pist'on, and-the apparatus is equalized enthe lo'W pressure side of the -puls'ator piston in la v'corre's'pondi ing manner to that already explained in connection withl the high pressure side.

The piston rod-y end of the motorpiston has somewhat smaller Working area (due to the 'area taken bythe piston frod,)- than theother end has, and it is near the fend of this end cenn'eicting tube Fl. that the valve is here shown. -Tlie force of the blow however is dependent largely upon the eiective Vpressure'.o'nwthe back of the piston. The 'tubehaving' the valve connection maybe lconnected i'iirth'e ccmpa'rt'ment at the kother endet the mQtor cylnerjby reversing the `tubes andiFQ in 'either the pulsator or the motor Tend bf tiieir cylinder connections.

he change in the air chamber'ecnnection `from the-high te 'the l-o'W pressure conipfartment or the reverse could 'also be made by setting the valy'ejcrank N half Way around on the 'crank 'shark l As' herein described the term compartlment 7 refers tothe air space in communica'- tion with 'one side of the pulsator piston. There are compartments one on each side'nf the said piston. The term Y ports refers to tire'pressure connections that Vjoin Ythe equalizer j'ch'amber 'with thev said com'- `endV and S2 cn t'e'back end. v

To more ei'ectiyely rtransmit-the Areciprocationfs Of ythe compressor pistonl to the tool piston, Ythe density of the yt'ransmitting meiurn is increased' by forcing more air into the chamber H by the 'small auxiliary airV compressor l which isk operatedfrom 4the :crank as Yshown in Fig. l, or in lany other 'suitable manner. The air fcrced'infto the system by the compressor K might be de'- fpar'tments' and are lettered S on theY front Yinfered t'o one 'of .the compartmentsinstead of to the airchanber H andthe equalizer valve 'Vl 'would stiil operate in the same ymanner to: maintain the'pneumati'c balance to and therefore only diagrammatically represented, in practice it is usually advisable in power picks to cushion the piston at both ends of its stroke. The size of the piston rod is also preferably smaller in proportion to the diameter of the cylinder than here shown (or a tail rod may be used on said piston) so that the effective pressure will act effectively on the piston rod side of the piston head as it will on the opposite side of the piston head.

Having described my apparatus I claim- 1. The combination in an air pulsator of a pulsator cylinder, a reciprocatory piston therein dividing the air space into two compartments, means to reciprocate said piston, an equalizer chamber, ports connecting it with both ends of said cylinder, an equalizer valve controlling both of said ports, means to positively operate said valve from a moving part of the pulsator to open said ports alternately and in time with the pulsator piston, and motor pressure connections opening into the said air compartments on both sides of the pulsator piston.

2. The combination in an air pulsator of a pulsator cylinder, a reciprocatory piston therein dividing the air space into two compartments, means to reciprocate said piston, an equalizer chamber', ports connecting it with both ends of said cylinder, an equalizer ports, means to positively operate said valve from a moving part of the pulsator to open said ports alternately and in time with the pulsator piston, motor pressure connections opening into the said air compartments on both sides of the pulsator piston, an auxiliary air compressor, pressure connections between the compressor cylinder and the above described air inclosure, and means to operate said compressor to introduce air into the inclosure.

3. The combination in an air pulsator of a pulsator cylinder, a reciprocatory piston therein dividing the air space into two compartments, means to reciprocate said piston, an equalizer chamber, ports connecting it with both ends of said cylinder, an equalizer valve controlling both of said ports, means to positively operate said valve from a moving part of the pulsator to open said ports alternately and in time with the pulsator piston, a motor pressure connection in one of said connecting ports, and a motor pressure connection in the end of the pulsator cylinder that is opposite from that of said port connection.

4. The combination in an air pulsator of a pulsator cylinder, a reciprocatory piston therein dividing the air space into two compartments, means to reciprocate said piston, an equalizer chamber, ports connecting it Copies of this patent may be obtained for valve controlling both of said with both ends of said cylinder, a spool shape equalizer valve controlling both of said ports, means to reciprocate said piston and to positively operate said valve to open said ports alternately and in time with the pulsator piston, said means comprising a crank shaft, a main crank and a valve crank thereon, a driving connection between said piston and main crank, a driving connection between the equalizer valve and the valve crank, motor pressure connections opening into the compartments on opposite sides of the pulsator piston, an auxiliary air compressor, pressure connections between the auxiliary compressor cylinder and the above described inclosure, and means to operate said auxiliary compressor to introduce air into the said inclosure.

5. The combination in an air pulsator of a pulsator cylinder and piston therein, an equalizer chamber and ports connecting it with both ends of said cylinder, a spool shape equalizer valve controlling both of said ports, means to reciprocate said piston and to positively operate said valve from a moving part of the pulsator to open said ports alternately and in time with the pulsator piston, a motor pressure connection opening in one of said connecting ports, and a motor pressure connection in the end of the pulsator cylinder that is opposite from said port connection.

6. The combination in an air pulsator of a pulsator cylinder, a reciprocatory piston therein dividing the air space into two compartments, means to reciprocate said piston, an equalizer chamber, ports connecting it with vboth ends of said cylinder, a motor pressure connection opening into one of said port connections, a motor pressure connection opening into the compartment opposite to that of the preceding motor pressure connections, an equalizer valve controlling both the said port connection on one end of the cylinder and the intersection of the motor connection with the port on the opposite end of the cylinder and allowing the passage of air between the equalizer chamber and both the motor cylinder and the pulsator cylinder simultaneously, and means to positively operate said valve to open said connections on opposite ends of the cylinder alternately and in time with the pulsator piston.

In testimony whereof, I sign the foregoing specification, in the presence of two witnesses.

`HARRY T. GETTINs,

V. C. LYNCH.

iive cents each, by addressing the Commissioner of Yatents,

Washington, D. C. 

